The rooms that most concern homeowners are the living room and kitchen, the survey found, the survey found.

But people’s concerns about their parents-in-law are not without foundation.

Sandstrom said that a third of the parents it interviewed confessed to having high expectations and expected their daughter or son-in-law to have up-to-date homewares and appliances.

Ben Lovett, a Sandstrom spokesman, said: “When we commissioned this study we had no idea just how much us Brits spend ahead of a visit from the in-laws.”

The company’s poll also found that Britons are more likely to spend time hiding items that might meet disapproval than buying presents for their in-laws. This does not diminish as people get older. One in ten over-55s admitted that they still hide “naughty” items such as cigarettes and alcohol when the in-laws come to stay.

Around 2,000 adults were polled for the survey, which was carried out for the company by One Poll.